<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>form</title>
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>

</head>
<body>
    <div id="root">
        <child>
            {{message}}
            <template v-slot:header="msg">
                {{msg.upMessage}}
            </template>
        </child>
        <br>
        <br>
    
    </div>
    <script type="module" src="./app.js"></script>
</body>
</html>